Garment cooling system

ABSTRACT

A protective garment for providing cooling including a network of flexible tubing completing a loop between two chambers thermally connected to solidified carbon dioxide. Heat transfer fluid alternately flows between the chambers to transfer heat from the garment to the heat sink. The pressure generated by gasification of the carbon dioxide as heat is absorbed in each chamber causes the alternate flow. A float valve in each chamber controls the admission and exhaustion of the gaseous carbon dioxide.

United States Patent [451 June 20, 1972 Esposito [54] GARMENT COOLING SYSTEM [72] inventor: John J. Esposito, Delran, NJ.

[73] Assignee: The United States of America as represented by the Secretary of the Navy [22] Filed: Dec. 21, 1970 [21] Appl. No.: 100,074

[52] US. Cl ..62/l67, 62/384, 62/259, 62/188, 128/1425 [51] Int. 1 25d 3/12 [58] Field of Search ..62/56, 165, 166, 167, 168,

[5 6] References Cited UNITED STATES PATENTS 2,383,486 8/1945 lsenbury ..62/384 3,295,594 1/1967 Hopper..... ...62/259 3,526,102 9/1970 Boylett ..62/25 9 Primary Examiner-William J. Wye Attorney-R. S. Sciascia and Henry Hansen [5 7] ABSTRACT 3 Claims, 2 Drawing Figures GARMENT COOLING SYSTEM STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION The present invention relates to garment cooling systems, and more particularly to an active heat sink garment cooling system which automatically recirculates cooling fluid through an integral flexible tubing network without any external power supply.

Various means have been devised in the prior art for augmenting the human body cooling mechanisms and fall generally into two classes, i.e., a passive system such as an insulated garment, and an active system utilizing powered cooling cycles. Of these the former is typically characterized by its bulkiness thereby reducing the wearers mobility, particularly in the areas of limb protection. The latter class typically relies on complex powered mechanisms generally including either a refrigeration cycle or a passtive heat sink where the heat sink requires a separate power source to circulate heat transfer fluid throughout the cooling cycle.

SUMMARY OF THE INVENTION Accordingly, it is the general purpose and object of the invention to provide an improved garment cooling system which utilizes and which converts a portion of the thermal energy generated by the wearer to circulate the heat transfer fluid. Another object of the invention is to provide an active cooling system which is relatively simple in construction and operation, and to provide an active cooling system which incorporates a common and readily available heat sink.

These and other objects are accomplished according to the present invention with two cooling chambers, one at each end of a flexible tubing network distributed within a protective garment or suit, each cooling chamber having one side in common with a vaporizable or sublimatable heat sink (such as solidified carbon dioxide) housing and a manifold connecting the housing with the cooling chambers. A valved manifold alternately connects either of the cooling chambers with the housing for pressurizing the respective cooling chambers by vapor or gas formed in the process of absorbing heat, the opposite chamber being vented. A volume of heat transfer fluid thus flows between the cooling chambers through the network.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 represents an angular view of a garment cooling system constructed according to the invention; and

FIG. 2 is a schematic diagram of the system of FIG. 1 showing the system in more detail.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1 a back pack cooling unit is suspended by straps 11 on the outside of a protective suit 13 on the back of the wearer. Right and left flexible hoses 12 are respectively connected between the bottom end of cooling unit 10 proximate the lateral sides thereof and fittings 16 disposed laterally on either side of the waist line of suit 13. A cover on the upper surface of cooling unit 10, attached by means known in the art, provides access to cooling unit 10. A filter cap 14 on the upper end of cooling unit 10 proximate the right lateral side thereof together with a manual shutoff valve 46 on the bottom side of unit 10 intermediate the right hose 12 and unit 10 provides for filling and shutoff in a manner described hereinafter.

As shown in FIG. 2, cooling unit 10 includes two lateral chambers 20 disposed on either side of a coolant housing 21 and having common surfaces therewith. Coolant housing 21 at its upper end includes an opening 22 closed by the access cover 15 which, when removed, allows for the insertion of a block of solidified carbon dioxide 25 and which, when installed, traps the sublimated carbon dioxide gas within housing 21. Other low-temperature vaporizable or sublimatable fluids or solids may be used without departing from the invention. Solidified CO, is particularly suitable due to its temperature and its relative safety in use. Proximate the upper end of housing 21 on either side thereof there is extending a manifold 23 connecting through corresponding openings 24 the upper end of the coolant housing 21 with the respective upper ends of the lateral chambers 20. Openings 24 are fonned in respective lower horizontal surfaces of manifold 23 with the upper sides thereof forming respective ball seats 27. Two cylindrical float guides 30 each disposed in a generally vertical direction are attached within the respective lateral chambers 20, each central axis thereof being generally aligned with the corresponding central axes of openings 24. Each float guide 30 is open at its upper end and closed at its lower end having lateral drain openings 31 proximate the lower ends thereof externally closed by corresponding flapper valves 32. Each float guide 30 contains a float 33 attached to a rod 34 which extends through opening 24 where it terminates in a ball valve 35 within manifold 23. Intermediate opening 24 and the upper end of float guide 30 rod 34 is attached to one end of a horizontal rod 36, the other end of rod 36 attaching to a second ball valve 37, ball valve 37 being disposed in a generally upward direction from rod 36. Ball valve 37 is formed to seat against a ball seat 38 formed on the lower side of a vent opening 40 through the upper external surface of the corresponding chamber 20. The length of rod 34 is determined according to desired flotation level of float 33 within float guide 30 as described herein below; the length of rod 36 is determined by the distance between the central axes of openings 24 and 40. Each lateral chamber 20 includes hose fittings 45 formed on the respective bottom surfaces thereof having corresponding one ends of flexible hoses 12 attached thereto. The other ends of hoses l2 connect to a left and right waist fittings 16 on suit 13. A flexible tubing network 50 is contained within a lining 55 of suit 13 contiguously attached thereto forming parallel loop sections between the right and left waist fittings 16, the loop sections connecting the respective hoses 12 thereby completing a loop between the right and left lateral chambers 20. Either one of the chambers 20 includes a filler cap 14 through which a predetermined quantity of heat exchange fluid 51 is introduced into the system. A manually operated valve 46 is formed within the corresponding fitting 45 such that the fluid 51 is initially contained within the chamber 20 provided with a filter cap 14.

In operation heat exchange fluid 51, such as water or water mixed with alcohol, is introduced into one of the lateral chambers 20 through filler cap 14 and the solid CO 25 is placed within the coolant housing 21 following which the access cover 15 and the filler cap 14 are closed. The heat exchange fluid then transfers its heat through convection and conduction to the solid CO sublimating it and producing carbon dioxide gas. The amount of heat transfer fluid originally introduced into one of the lateral chambers 20 is sufficient to overflow the upper end of float guide 30 displacing float 33 upwards and thereby raising ball valve 35 away from seat 27 and at the same time closing ball valve 37 against ball seat 38 such that the gaseous carbon dioxide being continuously formed within the coolant housing 21 by the heat transfer process is free to enter the filled lateral chamber 20 pressurizing said chamber. When the chamber 20 is pressurized valve 46 is opened the heat exchange fluid 51 is pushed through the tubing network 50 into the other chamber 20. Inthe other chamber flapper valve 32 remains closed until the fluid level reaches the upper end of the float guide 30, thus float 33 is raised and ball valve 35 is opened initiating a new cycle only when fluid 51 is completely transferred to the other chamber 20. In the first chamber 20 flapper valve 32 allows the fluid inside float guide 30to drop thereby allowing ball valve 35 to seat and ball valve 37 to open when the fluid is below the flotation level of the float determined by the length of rod 34. The amount of heat exchange within each cycle is generally related to the volume of gas generated by solid C0,. Accordingly, it is contemplated that various heat balances can be accommodated by appropriate means of adjusting the heat transfer path from the fluid to the solid C0,, e.g., selection of the contact area of the solid CO, 25 with the housing 21 thereby selecting the conductive area and the heat transfer rate within the system.

Some of the many advantages of this invention should now be readily apparent. The invention provides a simply accomplished heat transfer means across a large temperature gradient of a passive heat sink, such as solid G0,, at a temperature level acceptable for human comfort at the same timing utilizing the product of the heat exchange, i.e., the carbon dioxide thus generated, to power the heat exchange cycle.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A personal cooling system for protecting a human from high temperature exposure comprising, in combination:

an outer garment;

heat sink means operatively disposed on the outside of said garment for exchanging heat during vaporization, and including an expendable mass of cryogenic matter for vaporizing into gas in the process of heat exchange;

heat transfer means disposed within said garment thermally connected at either end to said heat sink means for transferring heat from said garment to said heat sink means, and including a flexible tubing network disposed within said garment forming a plurality of parallel loop sections commonly joined at the corresponding ends thereof, two closed chambers operatively connected one at each end of said tubing network, said chambers being thermally connected to said heat sink means, and a quantity of heat transfer fluid contained within the volume formed by said network and said chambers; and

pressurization means enclosing said heat sink means connected to the ends of said heat transfer means for powering said heat transfer means with the vaporization of said heat sink means, and including a closed housing formed between said two chambers and having respective sides in common therewith, a manifold connecting the upper end of said housing with respective upper ends of said chambers, two floats deployed in respective ones of said chambers and carried by said fluid, two first ball valves operatively connected to respective ones of said floats formed to close said manifold at a predetermined lower level of said fluid within said chambers, two second ball valves each respectively connected to said floats formed to open and vent said chambers at said predetermined lower level of said fluid, and limiting means disposed within said chambers for maintaining said floats at respective lower levels until said fluid reaches a predetermined higher level. 2. A personal cooling system according to claim 1, further comprising:

' said limiting means including cylindrical float guides vertically disposed within respective chambers containing said floats, said float guides being open at the upper end thereof and having respective lateral passages at the bottom end thereof, corresponding externally closed flapper valves disposed across said passages, whereby an increase in fluid within said chamber is excluded from the inside of said float guides until the fluid level reaches the upper end thereof.

3. A cooling system comprising: vaporizable heat sink means for exchanging heat during vaporization, and including an expendable mass of cryogenic matter for vaporizing into gas In the process of heat exchange;

heat transfer means adapted to be thermally connected to an object to be cooled and thermally connected to said heat sink means for transferring heat from the object to said heat sink means, and including a tubing network adapted to be disposed in thermal contact with the object, two closed chambers operatively connected one at each end of said tubing network, said chambers being thermally connected to said heat sink means, a quantity of heat transfer fluid contained within the volume formed by said network and said chambers; and

pressure utilization means enclosing said heat sink means and operatively connected to said transfer means for powering said transfer means with the pressure produced by vaporization of said heat sink means, and including a closed housing formed between said two chambers and having respective sides in common therewith, a manifold connecting the upper end of said housing with respective upper ends of said chambers, two floats deployed in respective ones of said chambers and carried by said fluid, two first ball valves operatively connected to respective ones of said floats formed to close said manifold at a predetermined lower level of said fluid within said chambers, two second ball valves each respectively connected to said floats formed to open and vent said chambers at said predetermined lower level of said fluid and cylindrical float guides vertically disposed within respective chambers containing said floats, said float guides being open at the upper end thereof and having respective lateral passages at the bottom end thereof, corresponding externally closed flapper valves disposed across said passages, whereby an increase in fluid within said chamber is excluded from the inside of said float guides until the fluid level reaches the upper end thereof. 

1. A personal cooling system for protecting a human from high temperature exposure comprising, in combination: an outer garment; heat sink means operatively disposed on the outside of said garment for exchanging heat during vaporization, and including an expendable mass of cryogenic matter for vaporizing into gas in the process of heat exchange; heat transfer means disposed within said garment thermally connected at either end to said heat sink means for transferring heat from said garment to said heat sink means, and including a flexible tubing network disposed within said garment forming a plurality of parallel loop sections commonly joined at the corresponding ends thereof, two closed chambers operatively connected one at each end of said tubing network, said chambers being thermally connected to said heat sink means, and a quantity of heat transfer fluid contained within the volume formed by said network and said chambers; and pressurization means enclosing said heat sink means connected to the ends of said heat transfer means for powering said heat transfer means with the vaporization of said heat sink means, and including a closed housing formed between said two chambers and having respective sides in common therewith, a manifold connecting the upper end of said housing with respective upper ends of said chambers, two floats deployed in respective ones of said chambers and carried by said fluid, two first ball valves operatively connected to respective ones of said floats formed to close said manifold at a predetermined lower levEl of said fluid within said chambers, two second ball valves each respectively connected to said floats formed to open and vent said chambers at said predetermined lower level of said fluid, and limiting means disposed within said chambers for maintaining said floats at respective lower levels until said fluid reaches a predetermined higher level.
 2. A personal cooling system according to claim 1, further comprising: said limiting means including cylindrical float guides vertically disposed within respective chambers containing said floats, said float guides being open at the upper end thereof and having respective lateral passages at the bottom end thereof, corresponding externally closed flapper valves disposed across said passages, whereby an increase in fluid within said chamber is excluded from the inside of said float guides until the fluid level reaches the upper end thereof.
 3. A cooling system comprising: vaporizable heat sink means for exchanging heat during vaporization, and including an expendable mass of cryogenic matter for vaporizing into gas in the process of heat exchange; heat transfer means adapted to be thermally connected to an object to be cooled and thermally connected to said heat sink means for transferring heat from the object to said heat sink means, and including a tubing network adapted to be disposed in thermal contact with the object, two closed chambers operatively connected one at each end of said tubing network, said chambers being thermally connected to said heat sink means, a quantity of heat transfer fluid contained within the volume formed by said network and said chambers; and pressure utilization means enclosing said heat sink means and operatively connected to said transfer means for powering said transfer means with the pressure produced by vaporization of said heat sink means, and including a closed housing formed between said two chambers and having respective sides in common therewith, a manifold connecting the upper end of said housing with respective upper ends of said chambers, two floats deployed in respective ones of said chambers and carried by said fluid, two first ball valves operatively connected to respective ones of said floats formed to close said manifold at a predetermined lower level of said fluid within said chambers, two second ball valves each respectively connected to said floats formed to open and vent said chambers at said predetermined lower level of said fluid and cylindrical float guides vertically disposed within respective chambers containing said floats, said float guides being open at the upper end thereof and having respective lateral passages at the bottom end thereof, corresponding externally closed flapper valves disposed across said passages, whereby an increase in fluid within said chamber is excluded from the inside of said float guides until the fluid level reaches the upper end thereof. 